Interpretive Summary: The European corn borer (ECB) is a major pest of corn in the U.S. ECB populations are often monitored with traps, but interpretation of trap data may be problematic because trap design, location, and weather may influence the number of captures of moths in the traps. The objectives of this experiment were, first, to examine differences in ECB-moth captures among the Intercept wing trap, the Intercept bucket/funnel UNI trap, and the Hartstack wire-mesh, 75-cm diameter cone trap (large metal cone trap), as well as among three cone trap designs. Second, we examined the influence of the location of the large metal cone trap relative to a windbreak on the number of moths captured. Third, we examined the relationship between nightly mean air temperature, relative humidity, wind speed, precipitation, and the number of moths captured in the large metal cone traps. The number of moths captured was influenced by trap design, with the large metal cone traps capturing the most moths. The wing and bucket traps were ineffective. Differences among trap captures were significant among the trap locations relative to a windbreak. Under moderate to strong wind speeds (>4 mph), traps located leeward of the windbreak captured the most moths, but when wind speeds were light (<4 mph), traps not associated with windbreaks captured the most moths. Nightly mean air temperature was the most important weather parameter influencing moth capture in the large metal cone traps, and the number of moths captured increased with temperature. Traps baited with a lure are often used in ecological studies to capture ECB males, and counts of moths from traps may aid workers in determining the relative size of moth populations and help workers determine when to scout cornfields for insect management.

Technical Abstract:
Pheromone-baited traps are often used in ecological studies of the European corn borer, Ostrinia nubilalis (Hubner). However, differences in trap captures may be confounded by trap design, trap location relative to a windbreak, and changes in local weather. The objectives of this experiment were, first, to examine differences in O. nubilalis-moth captures among the Intercept (trademark) wing trap, the Intercept (trademark) bucket/funnel UNI trap, and the Hartstack wire-mesh, 75-cm diameter cone trap (large metal cone trap), as well as among three cone trap designs. Second, we examined the influence of the location of the large metal cone trap relative to a windbreak on the number of moths captured. Third, we examined the relationship between nightly mean air temperature, relative humidity, wind speed, precipitation, and the number of moths captured in large metal cone traps. The number of moths captured was significantly influenced by trap design, with large metal cone traps capturing the most moths. Wing and bucket traps were ineffective. Differences among trap captures were significant among trap locations relative to a windbreak. Under strong (>14 kph) or moderate (7<14 kph) wind speeds, traps located leeward of the windbreak captured the most moths, but when wind speeds were light (<7 kph), traps not associated with windbreaks captured the most moths. The multiple regression model fitted to the relationship between number of moths captured per Julian date and nightly weather patterns was significant. Nightly mean air temperature was the most influential parameter in the model, and its relationship with moth capture was positive.